For example, as a valve for a CO2 cylinder used in a CO2 fire extinguishing apparatus or the like, a valve that can be opened rapidly by introducing a high pressure gas for starting is generally used. However, with this type of valves, the pressure on the outlet side cannot be limited. On the other hand, as a valve including a mechanism for reducing pressure, a cylinder valve provided with various reducing valves that is opened and closed by rotating a handle has been proposed. However, such a valve cannot be opened rapidly.
On the other hand, the inventors of the present invention developed a rapidly opening pressure regulating valve as disclosed in Japanese Unexamined Patent Publication JP-A 10-339383(1998) (FIGS. 7 to 10). However, in such a rapidly opening pressure regulating valve, the main body of the valve includes a plurality of members so that it is difficult to reduce the size, and the flow rate characteristics are not good.
The main body of a rapidly opening pressure regulating valve has to include a plurality of members for the following reason. FIGS. 12 to 14 are views showing the order of assembling a conventional rapidly opening pressure regulating valve. First, a valve member 222 is inserted in a middle body 210 from the upper end, and a valve component 221 is attached to the lower end of the valve member 222 that is projected from the middle body 210. Furthermore, a moving spring receptacle 207 and a spring 204 are inserted in the middle body 210 and a spring receptacle 203 is fixed. Then, these elements are threaded into a main body 201 and fixed thereto.
In order for the valve component 221 to serve as an open valve, the valve component 221 has to be larger than a valve seat 213 of the middle body 210, and therefore it is necessary to separate the valve member 202 into the main valve member 222 and the valve component 221, and to assemble these elements with the valve seat 213 sandwiched therebetween. In this case, the middle body 210 having the valve seat 213 is necessary, in view of the relationship between the size of the valve component 221 and the inlet nozzle portion 211 of the main body 201.
FIG. 15 is a cross-sectional view taken along line B1-B2 of FIG. 14. When opening the valve, the valve member 202 slides in the direction perpendicular to the drawing sheet from the nearer side to the farther side. In this case, fluid flows the direction perpendicular to the drawing sheet from the farther side to the nearer side, is guided by a plurality of fluid guiding ports 212b and led to an outlet 212a via a fluid guiding groove 212c. When the middle body 210 is threaded into the main body 201 and fixed thereto, the fluid guiding port 212b is not always fixed in the same direction. The flow rate in the outlet 212a is different between the case when the positions of the fluid guiding port 212b and the outlet 212a are displaced significantly and the case when the positions thereof are matched, so that the flow rate is varied, which affects the flow rate characteristics.